Timer

ABSTRACT

A timer device, which displays a load operation state, includes a clock counter, a load counter, a display and a controller. The display displays a count value of the load counter when the load counter is counting and displays a count value of the clock counter otherwise. The controller causes the display to flash in synchronism with the changing of the count of the load counter when the load counter is being operated.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a timer device including a clockcounter for determining real time and a load counter for controlling theoperating time of a load. In particular, the present invention relatesto a timer device having a display unit indicating the operation stateof the load.

2. Description of the Prior Art

Timers, such as for a combination coffee maker which automatically millsthe coffee beans, then drips water through the grounds, have been knownup to now. Such a known timer for a coffee maker has a clock counter fordetermining real time and a load counter controlling the milling time.The timer also has a display unit which usually displays the real timefrom the clock counter, but displays the count value of the loadcounter, i.e., the remaining milling time, during the milling operation.Further, the display of the display unit during the milling operation isflashed in synchronism with changes in the seconds unit of the clockcounter output to indicate that the device is milling.

A problem with this conventional timer is that the counting operation ofthe load counter is begun in response to the operation of a start keywhich starts the milling process. However, the counting operation of theload counter will not necessarily be synchronized with the second unitcounting action of the clock counter, because the time depression of thestart key will not necessarily be synchronized with the clock counter.Therefore, when the display of the count value of the load counter isflashed in response to changes in the seconds unit of the clock counter,the timing of the flashing display does not coincide with the timing ofthe switching over of the count value being displayed, causing thedisplay to be difficult to view and liable to be read in error.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved timerdevice wherein, when the display unit flashes the count from the loadcounter, the timing of this flashing can be made to coincide with thetiming of the change over the count value being displayed, thus avoidingthe risk of the display being read erroneously due to the displaybecoming difficult to view.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of this invention will becomemore apparent and more readily appreciated from the following detaileddescription of the presently preferred exemplary embodiment of theinvention, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows a block diagram of an embodiment of this invention appliedto a coffee maker;

FIG. 2 shows a front view of an operation panel;

FIGS. 3 and 4 show respective front views of different display states ofa display unit; and

FIGS. 5 to 7 are timing charts useful in explaining the operation of theembodiment of FIG. 1 in which: graph (a) in each of FIGS. 5-7 shows onesecond intervals of a seconds unit output of a one-minute counter; eachgraph (b) shows a flashing timing synchronized with the seconds unitoutput of the one-minute counter; each graph (c) shows each count valueof a load counter; each graph (d) shows a conventional display state ofa display unit; each graph (e) shows a flashing timing in the presentembodiment; and each graph (f) shows a display state of the presentembodiment.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENT

An embodiment of the present invention applied to a coffee maker will bedescribed in more detail with reference to the accompanying drawings.

Referring to FIG. 1, there is shown a block diagram of an embodiment. Acoffee mill motor 1 is connected to an AC power source 3 through a firstswitch 5 (normally open type). Coffee mill motor 1, serving as a load,drives a cutter (not shown) for milling coffee beans in a milling case.

A heater 7 for boiling water has one end connected to coffee mill motor1 through a thermal switch 9 and another end connected to power source 3through a second switch 11 (normally open type). The water boiled byheater 7 is fed to the mill case.

A timer device controlling the above-described circuit will be describedwith reference to FIGS. 1-4. A clock pulse generating circuit 13includes a light emitting diode 15, a photo-transistor 17 and a waveformshaping circuit 18. The cathode of light emitting diode 15 is connectedto AC power source 3 through an ordinary diode 19 and a resistor 21. Theanode of diode 15 is directly connected to power source 3. The collectorand emitter of photo-transistor 17 are connected to the input ofwaveform shaping circuit 18. Thus, the waveform shaping circuit 18produces 60 clock pulses P₁₈ per second from its output when the powersource is 100 V, 60 Hz single phase AC. the input of a one-minutecounter 23 is connected to the output of waveform shaping circuit 18.When one-minute counter 23 receives clock pulses P₁₈ from the clockpulse generating circuit 13, it divides clock pulses P₁₈ in frequency,performing a repetitive count operation in which 60 seconds of pulsesare divided into 1/10 second intervals. Then one-minute counter 23outputs a count signal S₂₃ from one of its outputs O_(a) having onepulse every second. One-minute counter 23 also produces one-minute pulseP₂₃ from the other of its outputs O_(b) once per minute. A frequencydividing circuit 25, whose input is connected to the output of waveformshaping circuit 18, divides the frequency of clock pulses p₁₈ so as tooutput one-second pulse P₂₅ every second. A clock-setting key (clocksetting means) 27, a milling-time-setting key (load operation timesetting means) 29, a start key 31 and a stop key 33 are provided on acontrol panel 35 as shown in FIG. 2. Depressing clock-setting key 27produces a high level clock-setting signal S₂₇. Depressingmilling-time-setting key 29 produces a high level milling-time-settingsignal S₂₉. Depressing start key 31 produces a high level start signalS₃₁. Depressing stop key 33 produces a high level stop signal S₃₃. Adisplay unit 37 mounted on control panel 35 is a four-figuresegment-type display.

The output of clock-setting key 27 is connected to one of the inputs ofan AND circuit 39. The other input of AND circuit 39 is connected to theoutput of frequency dividing circuit 25. The output of AND circuit 39 isconnected to the input of a clock counter 41 through a transfer gatecircuit 43. The input of clock counter 41 is also connected to the onepulse per minute output O_(b) of one-minute counter 23 through atransfer gate circuit 45. Clock counter 41, counting hours and minutes,outputs its counter signal S₄₁. The gate of transfer gate circuit 43 isconnected to the output of clock-setting key 27. The gate of transfergate circuit 45 is connected to the output of clock-setting key 27through an inverter circuit 46.

One of the inputs of an AND circuit 47 is connected to the output of themilling-time-setting key 29, the other input of which is connected tothe output of frequency dividing circuit 25. The output of AND gate 47is connected to the input of a milling-time-setting counter 49. Theoutput of milling-time-setting counter 49 is connected through atransfer gate circuit 51 to the pre-set input PR of a load counter 53consisting of a down-counter. Load counter 53 includes a clock input CK,output D and not-zero output NZ. The not-zero output NZ becomes low whenthe counting value of load counter 53 is 0 and is high level when thecounting value is other than 0. The clock input CK of load counter 53 isconnected to the output of waveform shaping circuit 18 through atransfer gate circuit 55, and the not-zero output NZ is connected to thegate of transfer gate circuit 55. In this case, the load counter 53includes a frequency dividing circuit which divides the frequency ofclock pulses P₁₈ which are supplied from waveform shaping circuit 18 tothe clock input CK through transfer gate circuit 55, therebydecrementing the count in load counter 53 once every second.

The output of start key 31 is connected to the set-input S of an RSflip-flop circuit 57. The output of stop key 33 is connected to thereset-input R of flip-flop 57. The Q output of flip-flop circuit 57 isconnected to the input of a delay circuit 59 having a delay time ofabout 100 msec. The set-output Q is further connected to the input of atrigger circuit 61 and one of the inputs of an AND circuit 63. The otherinput of AND circuit 63 is connected to the not-zero output NZ of loadcounter 53, the output of which is connected to a milling drive circuit65. The milling drive circuit 65 is so constructed that the first switch5 is closed while a high level milling drive signal S₆₃ is supplied fromAND circuit 63 thereto. The output of trigger circuit 61 is connected tothe gate of transfer gate 51. The output of delay circuit 59 isconnected to one of the inputs of AND circuit 67. The other input of ANDcircuit 67 is connected to not-zero output NZ load counter 53 throughinverter circuit 69. The output of AND circuit 67 is connected to a dripdrive circuit 71. Drip drive circuit 71 is so constructed that secondswitch 11 is closed while a high level drip drive signal S₆₇ is suppliedfrom AND circuit 67 thereto.

The construction of a control circuit 73 for controlling display unit 37is described as follows. The input of a discrimination circuit 75 isconnected to the output O_(a) of one-minute counter 23 through atransfer gate circuit 77, and is connected to the output D of loadcounter 53 through a transfer gate circuit 79. The gate of transfer gatecircuit 77 is connected to the output of AND circuit 67. The gate oftransfer gate 79 is connected to the output of AND circuit 63.Discrimination circuit 75 is so constructed that it outputs a high levelsignal when the value of the 1/10 second unit of the count signal fromload counter 53 (described below) is 0 or even 4, and outputs a lowlevel signal when the value is odd.

The output of discrimination circuit 75 is connected to one of theinputs of an AND circuit 81. The other input of AND circuit 81 isconnected to the output of an OR circuit 83. One of the inputs of ORcircuit 83 is connected to the output of AND circuit 63, and the otheris connected to the output of AND circuit 67. Further, the output of theAND circuit 81 is connected to one of the inputs of an OR circuit 85,the other input of which is connected to the output of a NOR circuit 87.One of the inputs of NOR circuit 87 is connected to the output of ANDcircuit 63 and the other input is connected to the output of AND circuit67.

The output of OR circuit 85 is connected to the gate of a transfer gatecircuit 89, the input of which is connected to the output of a displaymemory 91, the output of which is connected to the input of display unit37. Further, the output of milling-time-setting counter 49, output D ofload counter 53 and the output of clock counter 41 are connected to theinput of display memory 91 through a transfer gate circuit 93, 95 and97, respectively. The gate of transfer gate circuit 93 is connected tothe output of milling-time-setting key 29. The gate of the transfer gatecircuit 95 is connected to the output of an AN circuit 99. AND circuit99 has a first input connected to the output of milling-time-setting key29 through an inverter circuit 101, a second input connected to theoutput of clock-setting key 27 through an inverter circuit 103, and athird input connected to the output of AND circuit 63. In addition, thegate of transfer circuit 97 is connected to the output of a NOR circuit105, one of the inputs of which is connected to the output ofmilling-time-setting key 29, the other input of which is connected tothe output of AND circuit 99.

A DC constant-voltage power circuit 107 is connected to power source 3drops the voltage of AC power source 3 into a prescribed voltage, thenrectifies and stabilizes the prescribed voltage to supply the individualcircuits with the prescribed voltage as DC constant-voltage.

The operation of the above-disclosed embodiment will now be described.

First of all, when the clock-setting key 27 is pressed, the high levelclock-setting signal S₂₇ output from the key 27 is supplied to one ofthe inputs of AND circuit 39 and gate of transfer gate circuit 43simultaneously. Consequently, one-second pulses P₂₅ from the frequencydividing circuit 25 are supplied to clock counter 41 through AND circuit39 and transfer gate circuit 43. Thus, the value of clock counter 41 ischanged every second, every time a one-second pulse P₂₅ is supplied toclock counter 41. At this point, a high level milling-time-settingsignal S₂₉ is not produced from the milling-time-setting key 29. Sincethe output signal from AND circuit 99 is a low level, NOR circuit 105outputs a high level signal, which is supplied to the gate of transfergate circuit 97. The count signal S₄₁ from clock counter 41 is thereforesupplied to the input of the display memory 91 through the transfer gatecircuit 97. Furthermore, the output signals of AND circuits 63 and 67are low levels, so NOR circuit 87 produces a high level signal, which issupplied to the gate of transfer gate circuit 89 through OR circuit 85.The display unit 37 therefore displays the content of the display memory91, that is, the count value of clock counter 41. If clock-setting key27 is released when the display has reached the current time, e.g.,"1230" (12:30), as shown in FIG. 3, the output signal of invertercircuit 46 will become a high level, thus the one-minute pule P₂₃ fromthe output O_(b) of one-minute counter 23 is supplied to the input ofclock counter 41 through transfer gate circuit 45. The count value ofclock counter 41 therefore changes every time a one-minute pulse P₂₃ issupplied, i.e., every minute, and the display of display means 37 showsthe current time, such as "1231" (12:31), "1232" (12:32), . . .

When making coffee, a certain amount of the coffee beans correspondingto the desired amount of coffee is provided to the milling container,and a quantity of water corresponding to the amount of coffee beans issupplied to the water tank. When milling-time-setting key 29 isoperated, milling-time-setting key 29 produces a high levelmilling-time-setting signal S₂₉ which is supplied to one of the inputsof AND circuit 47. Consequently, one-second pulses P₂₅ from thefrequency dividing circuit 25 are supplied to the input ofmilling-time-setting counter 49 through AND circuit 47, causingmilling-time-setting counter 49 to increment by one every second when aone-second pulse P₂₅ is supplied. The high level milling-time-settingsignal S₂₉ is also provided to one of the inputs of NOR circuit 105.Consequently, it causes the output of NOR circuit 105 to become a lowlevel. As a result of that, transfer gate circuit 97 is off, preventingdisplay memory 91 from receiving the count-signal S₄₁ of clock counter41.

When a high level milling-time-setting signal S₂₉ is provided to thegate of transfer gate circuit 93, the count-signal S₄₉ ofmilling-time-setting counter 49 is provided to display memory 91 throughtransfer gate circuit 93. Thus, display unit 37 indicates the time setfor milling. If milling-time-setting key 29 is released when displayunit 37 is indicating the optimum milling time (for example, 7 secondsas shown in FIG. 4), milling-time-setting signal S₂₉ then ceases and thecounting operation of milling-time-setting counter 49 stops, so that thecount value is 7. It should be noted that when milling-time-setting key29 is released, display means 37 again indicates the current time,because when milling-time-setting signal S₂₉ ceases, transfer gatecircuit 93 is in the OFF state, and transfer gate circuit 97 is in theON state.

After that, if start key 31 is pressed for a short time, high levelstart signal S₃₁ is produced by start key 31. Flip-flop circuit 57 thenassumes a set state in response to the rise of start signal S₃₁, so thatits Q output changes from a low level to high level. Trigger circuit 61is then triggered in response to the rise of the output signal of theoutput Q to output a trigger pulse which is sent to the gate of transfergate circuit 51. The count signal S₄₉ of milling-time-setting counter 49is supplied to the pre-set input PR of load counter 53 through transfergate circuit 51 so that the count signal S₄₉ indicating the countingvalue 7, for example, is pre-set in load counter 53. Subsequently, theoutput signal of the not-zero output NZ of load counter 53 is invertedinto high level, both inputs of AND circuit 63 become high to output ahigh level milling drive signal S₆₃. The high level milling drive signalS₆₃ is supplied to milling drive circuit 65, which permits first switch5 to close, thereby energizing coffee mill motor 1 to rotate the cutterfor milling the beans. Since the high level output signal of thenot-zero output NZ of load counter 53 is also supplied to the gate oftransfer gate circuit 55, clock pulses P₁₈ from waveform shaping circuit18 are supplied to the clock input CK of load counter 53 throughtransfer gate circuit 55, to decrement load counter 53 once per second.Furthermore, the high level milling drive signal S₆₃ from AND circuit 63is supplied to the third input of AND circuit 99. At this time, thefirst input of AND circuit 99 is provided with a high level signal frominverter circuit 101 since milling-time-setting signal S₂₉ is not beingproduced, and its second input is also high due to inverter circuit 103,since clock-setting signal S₂₇ is not being produced. Therefore, ANDcircuit 99 produces a high level signal and feeds it to the gate oftransfer gate circuit 95. Count signal S₅₃ of load counter 53 is therebysupplied to the input of display memory 91 through transfer gate circuit95. Since the high level milling drive signal S₆₃ of AND circuit 63 isalso supplied to the gate of transfer gate circuit 79, count signal S₅₃of load counter 53 is supplied to the discrimination circuit 75 throughtransfer gate circuit 79. Thus when the 1/10 second units of the countvalue indicated by the count signal S₅₃ is 0 or even, the output signalof discrimination circuit 75 is a high level, and when it is odd, theoutput signal is a low level. Consequently, in this case the outputsignal of discrimination circuit 75 is a high level while the countvalue indicated by the count signal S₅₃ is 6, 4, 2, 0. The high levelsignal of discrimination circuit 75 is supplied to one of the inputs ofAND circuit 81. The high level milling drive signal S₆₃ is furthersupplied to the other input of AND circuit 81 through OR circuit 83, sothe high level output signal of discrimination circuit 75 is supplied tothe gate of transfer gate circuit 89 through AND circuit 81 and ORcircuit 85. The count values of 6, 4, 2 and 0 in the count signal S₅₃being memorized in display memory 91 is therefore fed to display unit37. Display unit 37 shows the flashing display with a period of 2seconds, illuminated for 1 second and extinguished for 1 second. Thatis, remaining milling time is displayed in the following manner: forsecond 7 the display is extinguished, for second 6 it is illuminated,for second 5 it is extinguished, for second 4 it is illuminated, . . . ,and for second 0 it is illuminated.

FIGS. 5-7 show the different modes of display between the presentembodiment and prior art. Graph (a) in each FIGURE, indicates each onesecond interval of the seconds unit (first unit of one-minute counter23). Graph (b), in each FIGURE, indicates the flashing timingsynchronized with the seconds unit of one-minute counter 23 (highcorresponds to a display state and low corresponds to a no displaystate).

FIG. 5 shows the case in which the milling operation is started (whenstart key 31 is pressed) at point A. The count value of load counter 53is shown in FIG. 5(c). Conventionally, the display flashes with the timeas shown in FIG. 5(b), so the display of the remaining milling time isas shown in FIG. 5(d). That is, the display of the count value changesduring the illumination period as is seen in FIG. 5(d). FIG. 5(e) showsthe flashing timing in the present embodiment. It can be seen that theflashing timing of the display coincides with the timing of the changeover of the display value as is illustrated in FIG. 5(f) which shows thedisplay of the remaining milling time in accordance with the presentembodiment.

FIG. 6 shows the case in which the start-point of the milling operationis the point B. FIG. 6(c), FIG. 6(d), FIG. 6(e) and FIG. 6(f) correspondto FIG. 5(c), FIG. 5(d), FIG. 5(e) and FIG. 5(f), respectively. In thiscase, since the point when start key 31 is pressed happens to be insynchronism with the point when the seconds unit of the clock changes,the same display is obtained in the conventional case and the presentembodiment. FIG. 7 shows the case in which the start-point of themilling operation is the point C. FIG. 7(c), FIG. 7(d), FIG. 7(e) andFIG. 7(f) correspond to FIG. 5(c), FIG. 5(d), FIG. 5(e) and FIG. 5(f),respectively. It can be seen that an irregular display is produced inthe conventional case.

After the display operation, when the count value of load counter 53goes to 0, the output signal of the not-zero output NZ is inverted intoa low level, AND circuit 63 ceases to output a high level milling drivesignal S₆₃, so milling drive circuit 65 opens first switch 5 to stop themilling operation. When, subsequently, the signal of the not-zero outputNZ of load counter 53 is inverted to a low level, the output signal ofinverter circuit 69 becomes high, so AND circuit 67 outputs a high leveldrip drive signal S₆₇. Drip drive circuit 71 closes second switch 11 toenergize heater 7, so that it starts to supply hot water into themilling container and thus starts the extraction of the coffee liquid.At this time, when AND circuit 63 ceases to output milling drive signalS₆₃, the output signal of AND circuit 99 becomes low. Thus, transfergate circuit 95 disables load counter 53 from feeding the count signalS₅₃ to display memory 91. Also, since the output signal from AND circuit99 is low and milling-time-setting signal S₂₉ is not being output, theoutput signal of NOR circuit 105 becomes high, so that the count signalS₄₁ of clock counter 41 is now supplied to display memory 91 throughtransfer gate circuit 97. Furthermore, the high level drip drive signalS₆₇ from AND circuit 67 is also supplied to the gate of transfer gatecircuit 77 to enable transfer gate circuit 77 to supply the count signalS₂₃ of one-minute counter 23 to the input of discrimination circuit 75.As a result, the output signal of discrimination circuit 75 is a highlevel when the count value of the seconds unit in the count signal S₂₃is 0 or even, and is low level when it is odd. This output signal issupplied to one of the inputs of AND circuit 81. At this time, the otherinput of AND circuit 81 is supplied with the high level drip drivesignal S₆₇ through OR circuit 83, so the high level output ofdiscrimination circuit 75 is fed to the gate of transfer gate circuit 89through AND circuit 81 and OR circuit 85. Display unit 37 thereforeindicates current time flashing with a period of two seconds.

It should be noted that during the milling operation or during the dripoperation as above-described or when the drip operation is completed, ifthe stop signal S₃₃ is produced by pressing stop key 33 for a shorttime, flip-flop circuit 57 is reset so that the output Q becomes low.Subsequently, each one of the inputs of AND circuits 63 and 67 becomeslow level to stop the output of milling drive signal S₆₃ and drip drivesignal S₆₇.

According to the present embodiment described above, during milling,display unit 37 is flashed in step with the count action of load counter53 which controls the milling time by down counting the remainingmilling time. Consequently, the timing of the flashing of the displaycan be synchronized with the timing of change over of the numberdisplay. This prevents users from reading the display incorrectly, sincethe flashing of the display occurs regularly, i.e., the number changesevery each flashing time of the display.

Although, in the above embodiment, the display of display unit 37flashes with a period of two seconds, the flashing period could be setto any desired value. Furthermore in this embodiment, the presentinvention was applied to a coffee maker, but the present invention couldbe applied to any electrical apparatus which is equipped with a clockcounter and a load counter and wherein the count value of the loadcounter is displayed as flashing while the load is being driven.

Many changes and modifications in the above-described embodiment couldbe carried out without departing from the scope of the presentinvention. Therefore, the claims should be construed to include suchmodifications.

What is claimed is:
 1. A timer device for controlling a loadcomprising:clock counter means for counting clock pulses having apredetermined period; load counter means for counting load pulses havinga predetermined period; means, responsive to said load counter means,for operating said load; means for displaying a count value of said loadcounter means when said load counter means is counting and fordisplaying a count value of said clock counter means otherwise; andcontrol means for making the display of the count value of said loadcounter means in said displaying means flash in step with the changingof the count value of said load counter means while said load countermeans is counting.
 2. A timer device according to claim 1, furtherincluding means for setting a desired load operation time in said loadcounter means.
 3. A timer device according to claim 2, further includingstart means for causing said load counter means to start counting.
 4. Atimer device according to claim 3, wherein said displaying meansincludes a display memory for storing the value of said clock countermeans or the value of said load counter means to be displayed.
 5. Atimer device according to claim 4, wherein said control means includesdiscrimination circuit means for outputting a high level signal to saiddisplaying means for predetermined ones of the count values of said loadcounter means, said high level signal causing said displaying means toproduce a display.
 6. A timer device according to claim 5, wherein saidpredetermined count values are 0 and even.
 7. A timer device accordingto claim 5, wherein said predetermined count values are odd.